Afterplanes or "trim tabs" are common on all motorboats up to 60' in length. A typical afterplane configuration includes a pair of port and starboard afterplanes, each hinged to the bottom portion of the transom, located at the stern of the boat. Each afterplane pivots up and down, via hydraulic pistons or the like, that are attached at one end to the afterplane and at the other end to the transom. The purpose of attaching such afterplanes to a boat is for stabilization as it travels across the water. For example, the stern of a motorboat that does not utilize afterplanes will settle in the water creating a "wall" of water that, during acceleration, the bow must push through. Afterplanes, however, help avoid this unnecessary upward or listing altitude of the bow of the boat.
Typically, during acceleration of the boat from a standstill or near standstill position, the boat operator lowers the afterplanes to a downward position, with respect to the stern of the boat, using a toggle or push-button switch. This downward position forces water against the underside of the afterplanes which consequently raises the stern of the boat while lowering the bow to help maintain the boat in a "plane" position. Once the boat is at cruising speed, the operator raises the afterplanes to a substantially horizontal position to sustain the boat in the desired planing position. Maintaining a boat on a plane is especially important with respect to high performance speedboats for substantially lowering the risk of flipping over the speedboat during hard acceleration. Such flipping may occur when the afterplanes are positioned too low in the water.
The starboard and port afterplanes may typically be operated independently from one another. This is desired when there is an imbalance of weight in the boat. For example, if the majority of the boat passengers are on the port side of the boat, the starboard side will raise up causing the boat to tilt. With afterplanes, the driver can lower only the port afterplane which, in turn, raises the port side to balance the boat.
A boat that is properly balanced in a plane position allows the main boat motors to work more efficiently since their propellers will be substantially parallel to the water surface. Further, a planed boat provides a smoother ride by preventing inherent "porpoising" of the boat, while increasing driver visibility.
Powering such motorboats are typically provided by single or twin screw inboard, outboard or inboard/outboard engines. However, fishing boats and the like often use auxiliary power for trolling speeds, via trolling motors.
Trolling motors are designed to be operational when the main engines are off. They provide quick and precise bursts of speed when fishing, so that the fisherman can easily and quickly follow a fish. Since trolling motors provide less power than the main engines and are often powered electrically, they are quieter and generate far less vibration. This is advantageous, since it prevents "spooking" the fish that the main engines may cause.
Trolling motors are usually attached either to the bow, where the trolling motor pulls the boat, or to the stern, where the motor pushes the boat. With respect to the trolling motors attached to the stern, it is known that a pair of trolling motors may be attached, one motor on the starboard side and the other motor on the port side. This configuration helps to prevent fishing line entanglement, vis-a-vis, trolling motors that are attached to the bow. Further, aesthetically speaking, trolling motors attached to the stern are less of an "eye sore" than trolling motors attached to the bow.
It is also known to have various types of motors fixedly attached on the top surface of a hydrofoil. For example, U.S. Pat. Nos. 4,995,839 and 5,017,165 of Havins describe a boat having a main motor attached to the center of the boat transom and a trolling motor attached to the port side of the transom. The trolling motor is directly mounted on top of a hydrofoil. The hydrofoil can be hydraulically positioned in an up-position when the main motor is operating and a down-position when the trolling motor is operating. However, the hydrofoil does not behave as a trim tab but rather the hydrofoil is used to automatically raise the trolling motor when the main motor is engaged. Thus, when the main motor is engaged the hydrofoil is forced out of the water at the same time raising the trolling motor with no planing effects realized.
An example of a prior art system having a pair of motors mounted onto a pair of corresponding trim tabs, is found in U.S. Pat. No. 4,832,642 of Thompson. In this system, a pair of pedal motors are directly mounted on the top surface of a hydraulic trimming vein located on opposite sides of the stern. However, as shown in FIG. 4 of Thompson, a portion of the blades of each pedal motor remains below the trimming vein, and thus is susceptible to damage when the boat travels in shallow waters. Further, the trimming veins described in Thompson are substantially the same size as the pedal motors and thus, offer little protection of the motors, as opposed to an elongated trimming vein.
Another prior art system describing a pair of trim tabs, is described in U.S. Pat. No. 2,886,462 of Jagiel. This reference describes a single outboard motor which is mounted on a frame that includes a pair of extending fins which act as trim tabs. Here, however, the fins use the force of the water to adjust and maintain the position of the outboard motor helping to plane the boat when the motor is engaged. Also the motor is positioned between the fins, offering no protection against potential damage to the propellers.
It is therefore an object of the present invention to provide at least one motor positioned onto an afterplane such that the propeller of the motor does not extend substantially beyond the peripheral boundaries of the afterplane.
Another object of the invention is to provide at least one motor positioned onto an afterplane, such that the afterplane has a cut-out portion for permitting water flow therethrough.
A further object of the invention is to provide at least one motor positioned onto an afterplane, such that each afterplane has an elongated shape to provide greater protection of the propeller.
A still further object is to provide in combination an afterplane and trolling motor which allows the operator of a boat to engage a main engine without a need for raising the trolling motor.
Various other objects, advantages and features of the present invention will become readily apparent from the ensuing detailed description and the novel features which will be particularly pointed out in the appended claims.